There is considerable practical difficulty in producing high voltage outputs, in the range of 1,000 to 20,000 volts D.C., from low voltage input sources, in the range of 10 to 28 volts D.C., with small physical size. It is recognized that when the components of a power supply are closely spaced it becomes quite difficult to control breakdown voltages across small physical sizes. Small size can be obtained by using relatively high switching frequencies. The later approach requires large step up ratios in the power supply transformer. For example, in order to construct a power supply with a 10 volts D.C. input and a 3,000 volts D.C., a transformer having a turns ratio of approximately 300:1 might be required. However, a small power transformer with a high turns ratio tends to have large parasitic inductances and capacitances. A large portion of the power into such a transformer goes into energy stored in these parasitic components. Driving such a transformer with a rectangular waveform tends to produce a rounded or sinusoidal output voltage. Although it is possible to work around such resonant effects, the result is that the power transformer is physically larger than it would be otherwise, since it is storing considerable energy in the parasitic components.
With the present invention, the parasitic effects are decreased thereby allowing the construction of compact high voltage power supplies.